7.20 The roof of a refrigerated truck compartment is of com- posite construction, consisting of a layer of foamed urethane insulation (1₂ = 50 mm, k, = 0.026 W/m.K) sandwiched between aluminum alloy panels (t₁ = 5 mm, kp = 180 W/m.K). The length and width of the roof are L = 10 m and W = 3.5 m, respectively, and the temper- ature of the inner surface is T, = -10°C. Consider con- ditions for which the truck is moving at a speed of V = 105 km/h, the air temperature is T.. = 32°C, and the solar irradiation is Gs = 750 W/m². Turbulent flow may be assumed over the entire length of the roof. T₁0 V.I FC Frank & Dave s Frozen Desserts for Those Who Dent Count Calories Tu 2, a (a) For equivalent values of the solar absorptivity and the emissivity of the outer surface (α = ε = 0.5), estimate the average temperature T of the outer surface. What is the corresponding heat load imposed on the refrigeration system? (b) A special finish (α = 0.15, & = 0.8) may be applied to the outer surface. What effect would such an application have on the surface temperature and the heat load? (c) If, with a = e = 0.5, the roof is not insulated (1₂ = 0), what are the corresponding values of the surface temperature and the heat load?

2. Calculate Passive House's energy demand. a, Calculate window U-value based on given data in figure. 0.117m 0.117m 0.134m C₂ Utotal Wglass-0.996m = 1.229m glass Uglass = 0.6- glass W window - 123m W m².c 0.117m 1.48m nwindow W m² °C Uframe = 1.6- Area₁ U₁ + Area2 U₂... + Area, * U₁ Area total b. With the calculated U value for the windows find out how much power needed to maintain 20°C in a home with outside of 0°C based on the following: the house having a square footprint 17 m by 17 m, walls 2.5 m high (Uwalls = 0.152 each of the four walls hosting two windows, and each window having an area of 2 m². The entry door area is 2.5 m² (Udoor = 0.65- ). What are the heat loss rates for the installed windows, the door, the walls, the ceiling, and the floor? What is the overall heat loss rate of the home? m². C 1. What do these calculated heat loss rate values mean? 2. What is the definition of the passive house? 3. What does the U-value represent? Use its unit as a hint and describe it…

An external wall of a building has a U value of 0.50 W/m^2K. The indoor temperature is21 degrees C and the outdoor temperature is -2.0 degrees C The steady-state heat loss is calculated to be 11.5W/m^2 The wall contains a layer of insulation 40 mm thick with a conductivity of0.035 W/mK. What would the insulation thickness need to be in order toreduce the steady state heat loss by 50%? answer = 0.11m ​​​​​​​please show all working

solve all 4, show assumptions and comments for each.